CN117284138A - Method for charging a motor vehicle - Google Patents

Abstract

The invention relates to a method (30) for charging a motor vehicle (2) comprising a control device (22) and an energy store (6) operated by means of the control device. A current charging parameter (38) is received from a charging infrastructure (34) by means of a control device (22), and a starting point in time (40) for charging the energy store (6) is determined on the basis of the current charging parameter. The current charging parameters (38) are received again by the control device (22) and the starting time point (40) is determined again when the checking time point (50) is located before the starting time point (40). The invention also relates to a motor vehicle (2) and a computer program product (28).

Description

Method for charging a motor vehicle

Technical Field

The invention relates to a method for charging a motor vehicle, a motor vehicle and a computer program product. The motor vehicle comprises a control device and an energy store operated by means of the control device.

Background

Motor vehicles, such as passenger vehicles, have a main drive for forward drive, the main drive increasingly comprising an electric motor. In this case, for example, only one or more electric motors are used for forward drive of the motor vehicle, so that the motor vehicle is designed as an electric vehicle. For this purpose, in an alternative, the motor vehicle additionally comprises an internal combustion engine, and is therefore a so-called hybrid vehicle. Typically, an accumulator, such as an (electrical) battery, is used to power the electric motor (Bestromung). The battery has a plurality of battery modules, which are mostly identical in structure to each other. Each of the battery modules in turn has a plurality of individual battery cells, some of which are electrically connected in series and some of which are electrically connected in parallel. Thus, a direct voltage, which is one or more times the direct voltage of the battery cells, is provided by means of each of the battery modules.

Charging infrastructure, such as charging piles, is commonly used to charge an accumulator. The charging infrastructure has a plug on the outside, which plug is plugged into a corresponding charging connection of the motor vehicle, for example. Different standards are used depending on the design of the charging coupling. For example, the charging post itself is designed, for example, to be stationary and to be directly electrically connected to a power supply system, by means of which the charging post is fed. Thus, by means of the charging post, a substantially unlimited number of charging processes can be performed and substantially no maintenance or only to a relatively small extent. Due to the direct connection of the charging post to the power grid, relatively large energy can be transferred in a short time, so that the energy store can also be charged in a relatively short time period.

An alternative to this is to use a so-called wall-mounted charging station as the charging infrastructure. The wall station is for coupling to a power grid and may be installed by a user, for example, in a garage. In this case, the wall-mounted charging station is fed with 400V three-phase current, wherein the maximum current strength is up to 32A or 48A, such a connection already being present in the garage or house. Since the connection of the wall-mounted charging station to the power grid is mostly guided via the house connection, the maximum energy that can be transferred is limited, and thus the charging process of the energy store is prolonged. In order to readjust the motor vehicle for operation at the fastest possible point in time, the energy store is therefore mostly fed with the maximum energy that can be taken up. On the one hand, this results in loading of the house connection. On the other hand, the energy store is not charged with maximum efficiency here.

In order to avoid overload of the house connection/network and/or also to avoid overload of the energy store when charging with maximum energy, it is often possible to set when the motor vehicle should be reused, i.e. when the charging process should be ended. Starting from this, a charging curve (Ladelofil, sometimes also referred to as charging characteristic) is selected, in which the starting point in time corresponds either to the current point in time or to a future point in time, depending on the charging parameters of the respective charging infrastructure, such as the maximum power that can be taken up. In this case, a charging curve is selected in which not only the load on the energy store but also the load on the respective power grid is reduced, wherein the energy store is still charged at the desired point in time. In this way, it is also possible to avoid the accumulator remaining at a relatively high state of charge for a long period of time.

When the start time point is reached, charging is started. However, it is possible here for the charging parameters to have changed up to the starting point in time. For example, the maximum callable power may increase due to the reduced current load of the grid. However, this maximally callable power is not fully utilized during charging, so that, for example, at the current point in time, i.e., the starting point in time, the optimal charging profile is not used. However, if the maximum power available for the charging infrastructure is reduced at the current point in time, the energy store can no longer be charged up to the desired point in time, so that the usability of the motor vehicle and also the comfort for the user of the motor vehicle is reduced.

Disclosure of Invention

The invention is based on the following tasks: a particularly suitable method for charging a motor vehicle is provided, as well as a particularly suitable motor vehicle and a particularly suitable computer program product, wherein the usability and/or comfort is advantageously increased.

According to the invention, the object is achieved in a method by a method for charging a motor vehicle, wherein the motor vehicle comprises a control device and an energy store operated by means of the control device, in which method a current charging parameter is received from a charging infrastructure by means of the control device, and a starting point in time for charging the energy store is determined on the basis of the current charging parameter; and re-receiving the current charging parameters and re-determining the start time point by the control device when the current charging parameters are at an inspection time point which is temporally before the start time point; the object is achieved in a motor vehicle having a control device and an energy store operated by means of the control device, and the motor vehicle is operated according to the method; and the task is solved in a computer program product by a computer program product comprising instructions which, when the program is implemented by a computer, cause the computer to implement the method. Advantageous refinements and designs are the subject matter of the solution according to the invention.

The method is used for operating a motor vehicle. The motor vehicle is preferably land-based and preferably has a number of wheels, of which at least one, preferably a plurality or all of the wheels are driven. Suitably, one of the wheels, preferably a plurality of wheels, is designed to be controllable. It is thus possible to move the motor vehicle independently of a specific traffic lane, for example a track or the like. In this case, the motor vehicle can be positioned essentially arbitrarily on a traffic lane, which is made in particular of asphalt, asphalt or concrete. The motor vehicle is, for example, a commercial motor vehicle, such as a truck (Lkw) or a passenger car. However, it is particularly preferred that the motor vehicle is a passenger vehicle (Pkw). Alternatively, the motor vehicle is a bicycle and is designed, for example, as a so-called electric scooter. Alternatively thereto, the motor vehicle is a scooter (Roller, sometimes also referred to as scooter) or a motorcycle.

In particular, the motor vehicle expediently has a drive, by means of which the forward movement of the motor vehicle is effected. The drive, in particular the main drive, is designed, for example, to be entirely electric, and the motor vehicle is an electric vehicle. In a further development, the motor vehicle additionally has an internal combustion engine, and the motor vehicle is a so-called hybrid motor vehicle. The motor vehicle includes an accumulator. Suitably, the possible electric motor is operated by means of an accumulator. The energy store is suitable for this, in particular for this purpose. Preferably, an inverter is arranged electrically between the energy store and the electric motor, by means of which inverter the supply of the electric motor is regulated.

By means of the energy store, a direct voltage is expediently provided, wherein the voltage is, for example, between 200V and 800V, and is, for example, substantially 400V. Preferably, the energy store comprises a battery, suitably a so-called high-voltage battery, and the energy store is a high-voltage energy store. The battery comprises, for example, a plurality of battery modules, which are electrically connected in parallel and/or in series with each other. The individual battery modules are expediently identical to one another in construction. Each of the battery modules suitably comprises a number of battery cells, which are electrically connected in parallel and/or in series with each other. Thus, the voltage provided by the battery is a multiple of the voltage provided by one of the battery cells.

The motor vehicle expediently has a charging connection. In particular, the charging connection is introduced into the body of the motor vehicle and is closed, for example, by means of a pivotable cover. The charging coupling is intended to be coupled to a (external) charging infrastructure and is suitable for this, in particular for this purpose. For this purpose, the charging connection has, for example, a plurality of contacts, suitably at least two contacts. The charging connection is in electrical contact with the energy store, so that a current flow can be achieved at least in part between the charging connection and the energy store. For example, the charging coupling is designed according to the type of the plug or has a cable. The charging coupling suitably meets certain criteria, such as a type 1 or type 2 criterion. In particular, the charging coupling has a locking portion, so that a coupling of the cable at the charging coupling can be achieved, wherein an unintentional detachment is avoided due to the locking portion.

The charging infrastructure is not part of the motor vehicle and is suitable, in particular arranged, designed to supply electrical energy, so that it can be extracted by the motor vehicle. For example, the charging infrastructure is a charging pile, which is designed in particular to be stationary or mobile. In this case, the charging pile is expediently fixedly connected to the foundation at least temporarily, even in the mobile embodiment. Alternatively, a socket (sometimes also called a socket), which for example directs single-phase or three-phase alternating current, is used as the charging infrastructure. In particular, the socket meets certain criteria. In another alternative, the charging infrastructure is a wall-mounted box.

Furthermore, the motor vehicle has a control device by means of which the energy store is operated. In this case, the energy store is set, for example, directly by means of a control device, and if the energy store is designed as a battery or comprises said battery, the control device is, for example, a battery management system. Here, for example, by means of a battery management system, how much power is drawn from the battery. Alternatively or in combination thereto, if the battery is charged, the amount of electrical energy fed into the battery is set by means of the battery management system. To this end, the battery management system suitably comprises a number of switches and/or dc voltage converters. The battery management system is preferably associated with the respective battery module, so that, for example, only one of the battery modules is charged and/or power is extracted from the battery module. In this case, it is possible, in particular, to select a plurality of battery modules among the battery modules of the battery and not to select at least one battery module among the battery modules. It is thus possible to avoid a specific state of charge of the battery module and thus to increase the service life.

However, it is particularly preferred if the control device also has further components, in particular an on-board computer, or if the control device is formed by means of the further components. The control device is expediently arranged distributed in the motor vehicle and comprises, for example, an on-board computer and possibly a battery management system. In particular, the control device is at least temporarily used for communication with the charging infrastructure, for example when the motor vehicle, i.e. the energy store, is to be charged. For this purpose, the control device expediently has corresponding components. The control device itself is suitably supplied with power by means of an onboard power system, in particular a so-called low-voltage onboard power system, which, for example, directs a dc voltage of 12V, 24V or 48V. For example, the vehicle electrical system is fed by means of an energy store. However, it is particularly preferred that the on-board power supply is fed by means of a separate further energy store, so that operation can be carried out independently of the energy store, which is preferably designed as a high-pressure energy store. For example, the two energy stores are connected to each other by a dc voltage converter, so that the further energy store can be charged by means of the energy store.

The method is configured to receive current charging parameters from the charging infrastructure by means of the control device. The current charging parameters include, in particular, the (current) maximum power available and/or the (current) maximum current available, i.e. the current that can be maximally provided by means of the charging infrastructure. Alternatively or in combination, the charging parameters include, for example, a period of time during which no electrical energy is provided for use by means of the charging infrastructure. The current charging parameters are received in particular via signal lines, which are in particular part of a possible (charging) cable by means of which the charging base is connected to the energy store via signal technology. For example, a request is first generated by the control device to the charging infrastructure, by which the charging parameters are transmitted to the motor vehicle, so that the charging parameters can be received by the control device. Alternatively, the charging parameters are provided, for example, always by means of the charging infrastructure and are requested for receipt by the control device.

Based on the current charging parameters, a starting point in time for charging the accumulator is determined. In this case, the starting point in time is determined in particular in the future and is additionally determined, for example, as a function of the current state of charge (SOC) of the energy store and/or the desired state of charge of the energy store at the desired point in time. For example, a desired point in time and/or a desired state of charge of the energy store is entered or otherwise preset by a user of the motor vehicle. For this purpose, the motor vehicle has, for example, corresponding input options, such as a touch pad/touch screen.

For example, in order to determine the starting point in time, a charging curve is first selected from a plurality of charging curves, which are stored, for example, in the motor vehicle. In this case, a charging curve is used, from among all charging curves, in which, when charging with charging parameters, the energy store is charged at a desired point in time according to a desired preset; and in this charging profile, the starting point in time from which charging must be correspondingly performed is the earliest in the future or relative to the current point in time. If a plurality of charging curves meet these criteria, a charging curve is used, for example, in which the load on the charging infrastructure and/or the energy store or other components of the motor vehicle is minimal or in which the efficiency is highest, for example. In a further alternative, a charging curve is used which has an effect on the current position of the motor vehicle. Alternatively or in combination with the mentioned options, a charging profile is used in which the duration between the end of charging and the desired point in time is at least or at least less than a preset threshold value. Thus, it is possible to avoid the motor vehicle from staying at a predetermined state of charge as desired without using the motor vehicle.

The starting time is defined here in particular such that, when charging is started at the starting time according to the respective charging profile, charging is performed with the charging parameters until the charging is completed at the desired time, so that the desired state of charge is achieved in particular. In this case, the charging is ended, for example, at the desired time point or a short period of time, for example, 1 hour, 0.5 hour or 0.1 hour, before the desired time point.

At the time of the test time (which is temporally before the start time), the current charging parameters, i.e. the charging parameters present at the time of the test time, are received again by the control device. In this case, a corresponding request is also sent to the charging infrastructure, for example, so that the current charging parameters are transmitted. Alternatively, the charging parameters are provided, for example, in each case by means of the charging infrastructure, and a request for the provided charging parameters is made at the time of the checking. In this case, the checking time is later than the time at which the charging parameter was first received. The checking time is located between the time point at which the starting time point is first determined and the starting time point in time, for example, half way between the two. Preferably, the examination time point is 0.5 hours, 1 hour, 2 hours or 3 hours before the start time point. The starting point in time is redetermined based on the (then) current charging parameters and a check is made accordingly. In summary, the charging parameters are checked at the check time points, so that the start time points are adapted accordingly when possible. Here, in particular, the charging profile that has been selected (if this is used) is initially maintained. In contrast, if the redetermined starting point in time is, for example, in the past due to a change in the charging parameters, for example, a further charging curve is used, by means of which the starting point in time is redetermined. In particular, when the redefined starting point in time is reached, charging is started, preferably starting the charging of a possible charging curve. In this case, in particular, electrical energy is taken from the charging infrastructure for charging.

Therefore, based on the method, it is checked whether the charging parameters have changed. For example, if the charging parameters are changed such that the desired state of charge cannot be reached at the desired point in time when charging is started at the initially determined starting point in time, the starting point in time is advanced according to the method. Thus, the charging process is prolonged in time, and it is still possible to reach the desired state of charge, or at least a relatively high state of charge, at the desired point in time. Thus, the usability of the motor vehicle and the comfort for the user are improved. In the case of a further change of the charging parameters, it is also possible, for example, to move the starting point in time further into the future and to use another charging profile, in order to reduce, for example, the load of the energy store and/or the load of the current supply of the charging infrastructure, in particular of the power grid. Alternatively, the charging curve is maintained and a desired point in time can only be manipulated within the active charging curve or another charging curve if the desired point in time is reached.

For example, if at the point in time of the check, due to a change in the charging parameters, the desired state of charge of the energy store can no longer be achieved at the desired point in time, then the charging of the energy store is expediently started substantially immediately by means of the charging infrastructure, so that at least the highest possible state of charge of the energy store is achieved. For this purpose, electrical energy is transferred from the charging infrastructure, in particular by means of a motor vehicle.

In particular, according to the method, the charging parameters are not continuously checked, but rather are checked, in particular discretely, for example only at the point of time of the check. Thus, the energy requirement for checking, i.e. for receiving the charging parameters and for redefining the starting point in time is reduced. Thus, for example, an overload of a possible on-board power supply, in particular a low-voltage on-board power supply, and/or an excessive energy demand, which would, for example, lead to a complete discharge of the further energy store, is reduced, so that the control device would no longer be ready for use. In this case, too, the energy store can no longer be charged.

For example, the determination of the checking time point is always performed or is performed only if the starting time point is more than a specific period of time, in particular more than 0.5 hours, 1 hour or 2 hours, from the current time point. In such a short period of time, the charging parameters do not change significantly, so that in this case excessive costs are avoided.

For example, when the starting time point changes, only the charging is changed accordingly, i.e. for example, the starting is advanced or delayed. However, it is particularly preferred that a notification is sent to the user of the motor vehicle when the starting point in time changes. Preferably, this occurs at each change of the start time point. Alternatively, a notification is sent to the user only if the desired state of charge cannot be reached at the desired point in time due to a change in the charging parameters. For example, the notification is output by the motor vehicle itself, for example on a display. Alternatively, the notification is sent, for example, to the user's mobile telephone, for example directly over a mobile network or through a server. In particular, the notification is presented to the user by means of an application of the mobile phone. Thus, the comfort is further improved. Based on this notification the user is made aware of, so that it is not surprising that the state of charge may change at the desired point in time.

For example, the time interval between the start time point, i.e. the initially determined start time point, and the examination time point is fixedly predefined and is, for example, 0.5 hours, 1 hour or 2 hours. The comparison alternatively relates to the time period between the starting point in time and the current point in time and is for example half or a quarter thereof. In particular, the examination time points are defined, i.e. preset, in terms of time intervals. In other words, according to the method, a starting point in time is determined and the time intervals are fixedly preset or otherwise determined, thereby generating an inspection point in time. In a development, the time interval is adapted, i.e. adapted, according to a previous charging process. The previous charging process is thus analyzed, and in particular the time interval and thus the current test time point is determined therefrom. For example, each charging infrastructure is assigned a respective time interval or a respective time interval for all charging infrastructures. By adapting, it is possible to select the inspection time point relatively close to the start time point, wherein it is still ensured that the desired state of charge of the energy store is reached at the desired time point. In particular, an algorithm is used for the adaptation. For example, it is possible for the user to adapt the adapted frame conditions, in particular via an interface, for example a possible touch screen of a motor vehicle. Alternatively or in combination, the frame conditions, for example parameters, are preset by the manufacturer or the shop, for example when the motor vehicle is located at the manufacturer or in the shop, or by means of a radio connection, in particular via an internet connection. In a further alternative, no adaptation is performed, but the time intervals may be adapted, for example, on the user side or on the manufacturer/shop side, for example by manual input or by an internet connection.

For example, the examination time point is always established, and thus the start time point is redetermined. However, it is particularly preferred that the redetermination of the starting point in time is carried out in dependence on the selected operating mode of the motor vehicle. In other words, the checking time point is established only in one or more specific operating modes and the starting time point is redetermined, while this does not occur in at least one other operating mode. Thus, the adaptation of the motor vehicle to the user is further improved. For example, it is possible here to select the operating mode for the motor vehicle once and to keep it until it is changed. Alternatively, it is necessary for the operating mode to be always re-selected after connecting the motor vehicle to the charging infrastructure, for example by means of a possible touch screen.

For this purpose, the advantages and/or disadvantages which result from the redetermining of the starting point in time, in particular by means of the touch screen output, are preferably used. The energy requirement for the control device is thereby reduced without redetermination, so that, for example, in the case of a comparatively far desired point in time, excessive loading of the control device and thus also increased energy consumption, which may lead to a complete discharge of a possible further energy store, are avoided. However, due to possible variations in the charging parameters, it is not ensured here that the desired state of charge of the energy store is also actually reached at the desired point in time.

For example, between the first determined point in time of the start point in time and the check point in time, the control device is in an operating state. However, it is particularly preferred that the device is controlled until the examination time point is placed in sleep mode. In other words, after the start time point and in particular also the check time point has been determined, the control device is put into a sleep mode, in particular into a standby mode. In the sleep mode, the energy requirement of the control device is reduced here. Once the checking time point has been reached, the control device is placed in the operating state again, so that the starting time point can be redetermined.

In summary, a current charging parameter is thus received from the charging infrastructure by means of the control device, and a starting point in time for charging the energy store is determined on the basis of the current charging parameter. Subsequently, the control device is placed in a sleep mode until a check time point, wherein the check time point is temporally before the start time point. Subsequently, i.e. after the end of the sleep mode at the checking time point, the current charging parameters are received again by means of the control device and the starting time point is determined again. The energy requirement is thus further reduced, wherein it is ensured that the energy store has the desired state of charge at the desired point in time on the basis of the redetermination of the starting point in time.

Preferably, the placing in the sleep mode is only effected in one or more specific modes of operation selectable by the user. In particular, one of the operating modes is such that the starting point in time is not redetermined and, for example, the control device is placed in sleep mode until the starting point in time, so that the energy demand is as low as possible, wherein, however, a relatively large uncertainty in the state of charge of the energy store arises at the desired point in time. In a further operating mode, the start time is redetermined in particular a plurality of times, for example once every minute or every 5 minutes, and the start time is adapted accordingly. In particular, the control device remains in the operating state substantially continuously. In a further operating mode, the control device is expediently placed in a sleep mode up to the examination time point, wherein preferably at least 0.5 hours is present between the time point at which the first determination of the start time point and the examination time point. In this alternative, the energy requirement is reduced, wherein at least a relatively high state of charge of the energy store can still be achieved. In a development, the control device is always placed in sleep mode until the examination time point, independently of the possible operating modes.

For example, the control device remains in the operating state from the point of time of the examination or is put into sleep mode until the redefined point of time of the start. In a further development, after the redetermining of the start time point, the control device is again placed in sleep mode until a second check time point. The second checking time point is located temporally before the redefined starting time point. At the second checking time, a redetermination of the starting time is preferably performed, for which purpose, in particular, the current charging parameters are first received again. For example, there are only two inspection points in time, or there are a plurality of such inspection points in time, at which the charging parameters are received and the start point in time is redetermined, respectively. In this case, the control device is expediently placed in a sleep mode between the test points in time, so that the energy demand is relatively low, the certainty that the charge state of the energy store corresponds to the desired charge state being relatively high. For example, the length of the time period between the inspection time points successive to each other is reduced or the length is the same.

The motor vehicle is, for example, a passenger car (Pkw), a truck (Lkw) or a passenger car. Preferably, the motor vehicle comprises an electric motor for propelling the motor vehicle, and the electric motor is preferably propelled via a current transformer. The motor vehicle further comprises a control device and an energy store operated by means of the control device. The energy store is provided here, for example, by means of a control device, or at least it is possible to change the setting of the energy store by means of a control device. The motor vehicle is operated according to a method in which a current charging parameter is received from a charging infrastructure by means of a control device and a starting point in time for charging the energy store is determined on the basis of the current charging parameter. The method starts, for example, when the motor vehicle is electrically and/or signally connected to the charging infrastructure. At a checking time point (which is temporally before the starting time point), the current charging parameters are received again by the control device and the starting time point is determined again. In particular, a method for charging a motor vehicle, in particular an energy store, is thus carried out.

The electric vehicle preferably comprises a control unit which is adapted, suitably arranged and set up for carrying out the method. Suitably, the control unit is an integral part of the control device. For example, the control device forms a control unit, and/or the control unit forms a control device. For example, the control unit is an Application Specific Integrated Circuit (ASIC) or comprises a microprocessor. In particular, the control unit comprises a memory on which a computer program product is stored, which computer program product causes a computer, when the program is implemented by the computer, in particular a microprocessor, to carry out the method.

The computer program product comprises a number of instructions which, when the computer program product (computer program product also abbreviated as program) is embodied by a computer, cause the computer to carry out a method for charging a motor vehicle comprising a control device and an energy store operated by means of the control device. In this case, a current charging parameter is received from the charging infrastructure by means of the control device, and a starting point in time for charging the energy store is determined on the basis of the current charging parameter. At a checking time point (which is temporally before the starting time point), the current charging parameters are received again by the control device and the starting time point is determined again.

The computer is expediently part of and is formed, for example, by a control unit or an electronic device. The computer preferably comprises or is formed by means of a microprocessor. The computer program product is for example a file or a data carrier containing an implementable program which when installed on a computer automatically carries out the method.

The invention also relates to a storage medium on which the computer program product is stored. Such a storage medium is for example a CD-ROM, DVD or blu-ray disc. Alternatively to this, the storage medium is a USB flash disk or other memory, which is for example rewritable or writable once only. Such memory is, for example, flash memory, RAM or ROM.

The improvements and advantages explained in connection with the method are also transferred in the sense of a motor vehicle/computer program product/storage medium and to each other and vice versa.

Drawings

One embodiment of the invention is explained in more detail below by way of illustration. Here:

fig. 1 schematically and simply shows a motor vehicle, and

fig. 2 shows a method for charging a motor vehicle.

Detailed Description

The components corresponding to each other are provided with the same reference numerals throughout the figures.

Fig. 1 schematically shows a motor vehicle 2 in the form of a passenger car (Pkw). The motor vehicle 2 has a plurality of wheels 4, of which at least some are driven by means of electric motors, not shown in detail. The one or more electric motors are fed via an energy store 6 via a not shown converter. The energy store 6 has a battery 8, by means of which a direct voltage of 400V is supplied. Thus, the battery 8 has a high-voltage battery. The battery 8 has a plurality of battery modules, not shown in detail, which are identical in structure to one another and each comprise a plurality of battery cells, which are electrically connected in parallel and/or in series. The battery 8 is operated by means of a battery management system 10 of the accumulator 6. In this case, the battery management system 10 is used to select the respective battery module from which energy should be extracted in order to supply the electric motor, for example, or to charge the battery module. Power may also be transferred from one of the battery modules to another battery module by means of the battery management system 10.

The motor vehicle 2 has a charging connection 12, which is electrically connected to the energy store 6. Thus, transfer of electrical energy from the charging coupling 12 to the battery 8 or back is accomplished by the battery management system 10. The battery management system 10 is connected signal-technically to a bus system 14 of the motor vehicle, to which an input device 16 in the form of a touch screen is also connected signal-technically, which input device is arranged in an interior space of the motor vehicle 2, which is not shown in detail. In this case, it is possible for the user of the motor vehicle 2 to make (user) inputs via the input device 16. A radio device 18 operating according to the mobile radio standard is also connected to the bus system 14 in signal technology. It is thus possible to transmit data via the radio 18 to a server, not shown in detail. The control unit 20 is also connected to the bus system 14. The control unit 20, the radio 18, the input device 16 and the battery management system 10 are components of a control device 22, by means of which the energy store 6 is operated and the control device 22 is suitably formed. The control devices 22 are distributed in a decentralized manner in the motor vehicle 2. The control device 22, i.e. its respective components, is supplied with power by means of a vehicle electrical system, not shown in detail, by means of which a direct voltage of 48V is provided. In other words, it relates to a low-voltage on-board electrical system. The on-board power supply is fed by means of a further energy store, not shown, in the form of a battery, by means of which a direct voltage of the value 48V is supplied.

The control unit 20 comprises a computer 24 in the form of a microprocessor and a memory 26. A computer program product 28 is stored in the memory 26. The computer program product 28 (also referred to as a computer program or program) comprises a plurality of instructions which, when implemented by the computer 24, cause the computer to carry out the method 30 for charging the motor vehicle 2 shown in fig. 2. In other words, motor vehicle 2 operates according to method 30.

The method 30 is performed here when the motor vehicle 2 is connected to a charging infrastructure 34 by means of a charging cable 32 (also referred to simply as cable). The charging cable 32 is fixedly connected to a charging infrastructure 34, for example. Alternatively, the charging cable 32 is not only detachably connected to the charging infrastructure 34, but is also associated with the motor vehicle 2, for example. For connection, the charging cable 32 is inserted into the charging connection 12 of the motor vehicle 2. The charging cable 32 has a plurality of individual cores, wherein some of the cores are used for transmitting electrical energy and others are used for transmitting data.

In a first operation 36, current charging parameters 38 are received by the control device 22, which are provided by the charging infrastructure 36 and are transmitted to the motor vehicle 2 by means of the charging cable 32. In this case, the charging parameters 38 are transmitted by means of a core for signal transmission and are received, for example, by the battery management system 10 and fed into the bus system 14 by the latter. The charging parameter 38 has the current maximum output electrical power (value) by means of the charging infrastructure 34, which is time-dependent, for example. Based on this, a starting point in time 40 for charging the energy store 6 is determined by means of the control device 22, i.e. the control unit 20. For this purpose, the desired point in time entered by the user via the input device 16 and the desired state of charge of the energy store 6 at the desired point in time are used, i.e. for example whether the energy store should be fully charged or charged to a certain percentage. In this case, a charging curve of a plurality of charging curves for charging the energy store 6 is selected on the basis of the charging parameter 38 taking into account the desired point in time and the desired state of charge, with which charging curve the starting point in time 40 is in the future and with which the energy store 6 is charged most effectively under these boundary conditions. A starting point in time 40 is defined as a function of the selected charging profile, which corresponds to a point in time at which charging must begin, whereby the desired state of charge is reached at the desired point in time.

In a subsequent second working step 42, the user is requested to input an operating mode 44 via the input device 16, wherein the advantages and disadvantages of the selectable operating mode 44 are listed. In one of the operational modes 44, until the start time point 40 is entered, the control device 22 is placed in the sleep mode 46. When the start point in time 40 is reached, a third operating step 48 is carried out, in which the control device 22 is again transferred into the operating state. In a third step 48, the charging of the energy store 6 is started in response to the selected charging profile, for which purpose the electrical energy provided by the charging infrastructure 34 is fed into the battery 8 by means of the battery management system 10. For this purpose, for example, the interconnection (verschalting) of the cells 8 is changed. Preferably, a request is made by the battery management system 10 to the infrastructure 34 at a start time point 40 in order to start charging. Because the control device 22 is placed in the sleep mode 46 between the second and third work steps 42, 48, the energy requirements are relatively low. It is however possible that the accumulator 6 can no longer be fully charged to the desired state of charge at the desired point in time due to a change in the charging parameter 38, for example the maximum electrical power output of the charging infrastructure 34 is now reduced.

In the further operating mode 44, a fourth operating step 52 is therefore carried out between the second and third operating steps 42, 48 at the checking time 50, whereby the advantages and disadvantages of this operating mode 44 are also presented to the user by means of the input device 16, so that the user can select said operating mode. In this case, the fourth operating step 52 is only executed independently of the selected operating mode 44 if a time point of the start time 40, i.e. a time period greater than 0.5 hours between the first operating step 38 and the checking time 50, is determined.

In a fourth operating step 52, i.e. at the checking time 50 (which is temporally before the starting time 40), the current charging parameter 38 is received again by the control device 22 and the starting time 40 is determined again. If the charging parameters 38 change, it is possible that from now on another charging profile has to be selected or that the starting point in time 40 is shifted in order to still reach the desired state of charge at the desired point in time. Thus, for example, in the case of an increase in the maximum outputtable power of the charging infrastructure 34, the start time 40 is moved further toward the future, or in the case of a decrease in the maximum outputtable electric power, the start time 40 is moved toward the inspection time 50.

If the start time point 40 changes, a notification 54 is sent to the user. To this end, the notification 54 is output by means of the input device 16 and is directed to the server by means of the radio device 18, so that the notification can be received by means of the application of the user's mobile phone.

In a variant or at least in one operating mode 40, nothing happens until a newly determined starting point in time 40 is entered, and when this point in time is reached, a third operating step 48 is again carried out. In contrast, in one or more further operating modes 44, the fourth operating step 52 is then carried out again at intervals, i.e. at the second or further test time 50. In this case, the second and possibly further checking points in time 50 always precede the (respectively redefined, current) starting point in time 40. In other words, the fourth working step 52 is always performed temporally before the third working step 48. For example, the number of inspection points in time 50 is stored in the selected operating mode 44, or a time interval between the individual inspection points in time 50 is preset according to the selected operating mode 44.

In summary, the fourth operating step 52, in which the respective current charging parameter 38 is received and the starting point in time 40 is in each case redetermined, is thus carried out a plurality of times in succession in time. Where appropriate, a corresponding notification 54 may also be sent to the user. Since the starting time 40 is checked several times in this way, the third operating step 48 is carried out at a time point at which it is ensured that the energy store 6 actually also has the desired state of charge at the desired time point.

The time period between the successive executions of the fourth working step 52 is here always greater than 10 minutes and is, for example, constant. Comparison alternatively, the interval between these fourth working steps shortens as the (respectively current) starting point in time 40 is approached. In particular, the time interval between the start time 40 and the (corresponding) check time 50 is related to the previous charging process, i.e. to the already executed method 30. If the charging parameters 38 change relatively frequently during these previous charging processes, the time interval is chosen to be relatively short so as to be able to react to the change. In contrast, if the charging parameter 38 only changes slightly during the previous charging process, i.e. in the already performed method 30, the time interval increases.

The fourth operating step 52 is carried out in two different operating modes 44, so that the redetermination of the starting point in time 40 takes place as a function of the selected operating mode 44 of the motor vehicle 2. In one of the operating modes 44, the control device 22 remains continuously in the operating state. It is thus possible to select the time interval between the respective examination time 50 and the respective associated current starting time 40 to be relatively small, since, due to the continuous operation, the control device 22 has no further energy requirements. It is thus ensured that the energy store 6 has the desired state of charge at the desired point in time. However, the energy requirement of the control device 22 increases here. In this case, it is possible that, as a result of the increased energy requirement, the further energy store for feeding the control device 22 is completely emptied if the desired point in time is relatively far in the future. In this case, the motor vehicle 2 is no longer available and the further energy store must first be charged again and the motor vehicle 2 configured.

Thus, in another operating mode 44, in which the fourth operating step 52 is performed (multiple times), the control device 22 is placed in the sleep mode 46 in the second operating step 42, so that the control device 22 is in the sleep mode 46 until the examination point in time 50. At the check point in time 50, the control device 22 is again shifted into the operating state, so that the charging parameters 38 can be received again and the start point in time 44 can be determined again. Subsequently, the control device 22 is placed again in the sleep mode. Accordingly, the control device 22 is also in the sleep mode 46 correspondingly in the period between re-execution of the fourth operating step 52, so that the energy demand does not increase excessively even in the event of an increase in the number of examination time points 50. In summary, the control device 22 is thus placed in the sleep mode 46 again after the test time 50 until a second test time 50, wherein the second test time 50 is also temporally before the redefined start time 40. In a third operation step 48, the control device 22 is again also placed in the operating state.

In this operating mode 40, the energy requirement of the control device 22 is reduced, so that the possibility of a further accumulator emptying is substantially precluded. In this way, it is also ensured that the accumulator 6 has the desired state of charge at the desired point in time.

The invention is not limited to the embodiments described above. Conversely, other variants of the invention may also be derived therefrom by those skilled in the art without departing from the subject matter of the invention. Furthermore, in particular, all the individual features described in connection with the embodiments can be combined with one another in other ways without departing from the subject matter of the invention.

List of reference numerals

2 motor vehicle

4 wheel

6 accumulator

8 battery

10 battery management system

12 charging connection

14 bus system

16 input device

18 radio device

20 control unit

22 control apparatus

24 computer

26 memory

28 computer program product

30 method

32 charging cable

34 charging infrastructure

36 first working procedure

38 charging parameters

40 start time point

42 second working procedure

44 mode of operation

46 sleep mode

48 third working procedure

50 check time point

52 fourth working procedure

And 54 notification.

Claims (8)

1. A method (30) for charging a motor vehicle (2) comprising a control device (22) and an energy store (6) operated by means of the control device, in which method,

-receiving a current charging parameter (38) from a charging infrastructure (34) by means of the control device (22), and determining a starting point in time (40) for charging the accumulator (6) based on the current charging parameter; and is also provided with

-re-receiving the current charging parameter (38) by means of the control device (22) and re-determining the start time point (40) when the checking time point (50) is temporally before the start time point (40).

2. The method (30) of claim 1, wherein the notification (54) is sent to the user in the event that the start time point (40) is changed.

3. The method (30) according to claim 1 or 2, characterized in that the selected time interval between the start time point (40) and the check time point (50) is adapted according to a previous charging process.

4. A method (30) according to any one of claims 1 to 3, characterized in that the redetermination of the starting point in time (40) is performed in accordance with a selected operating mode (44) of the motor vehicle (2).

5. The method (30) according to any one of claims 1 to 4, wherein the control device (22) is placed in a sleep mode (46) until the examination point in time (50).

6. The method (30) of claim 5, wherein the control device (22) is re-placed in the sleep mode (46) until a second examination time point (50), wherein the second examination time point (50) is temporally before the re-determined start time point (40).

7. A motor vehicle (2) having a control device (22) and an energy store (6) operated by means of the control device, and which is operated according to a method (30) according to any one of claims 1 to 6.

8. A computer program product (28) comprising instructions which, when the program is implemented by a computer (24), cause the computer to implement the method (30) according to any one of claims 1 to 6.